UI embellishments can only produce surface delight; deep delight can only be achieved in functional, reliable, and usable interfaces.
Deep delight is holistic, and is achieved once all user needs are met, including functionality, reliability, usability, and pleasurability. Users may have a poor experience on a site, and yet feel surface delight occasionally. But deep delight only occurs when the user has reached a state of “flow” — that is, immersed productivity without much distraction from the main task. In other words, deep delight is experienced when the interface behaves like a surgeon’s knowledgeable assistant: it hands all the right instruments exactly when they are needed, without getting in the way.